2D versus 3D roadmap for uterine artery catheterization: impact on several angiographic parameters

Value of Dyna CT in guiding embolization during transarterial uterine artery embolization of fibroids

The present study aimed to assess the usefulness of Dyna CT during transarterial uterine artery embolization (UAE) of fibroids. A total of 65 patients with symptomatic submucosal and intramural fibroids scheduled for transarterial UAE at the First People's Hospital of Changhou between May 2016 and September 2018 were included. Dyna CT and routine digital subtraction angiography (DSA) were performed in all patients during angiographic embolization of the bilateral internal iliac arteries. The visualization qualities of uterine artery origin and fibroids, as imaged by Dyna CT, were compared with DSA anterior-posterior images. Dyna CT provided excellent 3-dimensional visualization of vascular structures of the bilateral internal iliac arteries and uterine artery origin. Dyna CT was primarily useful in patients with overlapped uterine arteries or complex vascular anatomies on DSA anterior-posterior images (Dyna CT 100% vs. DSA anterior-posterior 69.2%, P=0.03). However, stained fibroids were identified in 57/65 cases (87.7%) by Dyna CT, and in all of the cases (100%) by DSA anterior-posterior imaging (P=0.03). Dyna CT is not suitable for procedural evaluation when used alone for transarterial UAE of fibroids. However, Dyna CT is an excellent supplement to DSA anterior-posterior imaging, as it provides additional information to aid in treatment planning.

Long-term outcome and pre-interventional predictors for late intervention after uterine fibroid embolization

OBJECTIVES

To assess the long-term freedom of surgical conversion after uterine fibroid embolization (UFE) and to define predictors for better clinical outcome. Additionally, the potential of pregnancy after UFE is assessed.

STUDY DESIGN

Single-center retrospective cohort study including 190 patients who underwent UFE between 2001 and 2016. Data were obtained by postal questionnaire including symptom severity, late reintervention rate and post procedural fertility. Patient characteristics were extracted from the patients' electronic medical records. The cumulative rate of freedom from treatment failure was determined by Kaplan-Meier analysis. Cox regression models were used for univariate analyses of the association between patient preinterventional characteristics and late surgical conversion. Secondary outcome measures were patient specific predictors of treatment failure and evaluation of post-procedural fertility.

RESULTS

Long-term follow-up was available for a median of 6.1 years (range 1.2-15.2 y) in 95 out of 190 patients (50 %). Freedom from treatment failure showed a cumulative rate of 72.9 % after 10 years and stable until end of follow-up. A 63.8 % reduction in symptoms and a 23.3% increase in quality of life was found. Significant increase of treatment failure was found in patients with increasing pre-interventional uterine volume (p = 0.0003) or dominant fibroid volume (p = 0.0042); 9 out of 23 patients (39.13 %) with child-bearing wish became pregnant and conceived one or more children after UFE.

CONCLUSION

UFE is associated with sustained long-term symptom control. Larger size uterus or dominant fibroma are correlated with higher late surgical conversion rate. Last, women can become pregnant and deliver after UFE.

The factors contributing to the total radiation exposure of patients during uterine artery embolisation

Uterine artery embolisation (UAE) is an interventional angiography procedure for the treatment of symptomatic fibroids and/or adenomyosis in women. UAE is a less invasive and non-surgical alternative to hysterectomy or myomectomy. However, ionising radiation is used for both fluoroscopic and angiographic image guidance to visualise and access the uterine arteries for embolisation and treatment of these benign conditions. Identifying the contributors and implementing dose reduction techniques are particularly important as UAE patients are usually of child-bearing age. The purpose of this review was to examine the progression of literature on radiation exposure measurements and identifying the factors contributing to the total radiation exposure of female patients undergoing UAE. A Medline, ProQuest Central, ScienceDirect and Scopus database search from 2000 to 2018 was performed and forty articles were deemed acceptable for review following the inclusion and exclusion criteria set. UAE is a viable alternative to hysterectomy and myomectomy, as the reviewed literature demonstrated that the reported radiation exposure doses appear to be below the threshold for any deterministic radiation risks. The total radiation exposure of UAE patients is affected independently by multiple patient, operator expertise and technique, angiographic imaging and x-ray unit variables. Uterus preservation can be attained post-UAE with dose reduction and optimisation, however, a longitudinal study on UAE patients and their risk of radiation-induced deterministic and/or stochastic effects is recommended.

A new imaging technology to reduce the radiation dose during uterine fibroid embolization

BACKGROUND

Uterine fibroid embolization (UFE) is a minimally invasive imaging-guided treatment using radiation exposure.

PURPOSE

To compare the patients' radiation exposure during UFE before and after introduction of a new X-ray imaging platform.

MATERIAL AND METHODS

Forty-one patients were enrolled in a prospective, comparative two-arm project before and after introduction of a new X-ray imaging platform with reduced dose settings, i.e. novel real-time image processing techniques (AlluraClarity). Demographic, pre-interventional imaging, and procedural data, including dose area product (DAP) and estimated organ dose on the ovaries and uterus, were recorded and angiographic quality of overall procedure was assessed.

RESULTS

There were no significant differences in demographic characteristics and preoperative fibroid and uterine volumes in the two groups. The new imaging platform led to a significant reduction in mean total DAP (102 vs. 438 Gy.cm²; P < 0.001), mean fluoroscopy DAP (32 vs. 138 Gy.cm²; P < 0.001), mean acquisition DAP (70 vs. 300 Gy.cm²; P < 0.001), and acquisition DAP estimated organ dose in ovaries (42 vs. 118 mGy; P < 0.001) and uterus (40 vs. 118 mGy, P < 0.001), without impairment of the procedure and angiographic image quality.

CONCLUSION

A substantial 77% reduction of DAP values and 64% and 66% reduction in organ dose on ovaries and uterus, respectively, was demonstrated with the new imaging platform, while maintaining optimal imaging quality and efficacy.

Monoplane 3D Overlay Roadmap versus Conventional Biplane 2D Roadmap Technique for Neurointervenional Procedures

Purpose

We investigated whether a 3D overlay roadmap using monoplane fluoroscopy offers advantages over a conventional 2D roadmap using biplane fluoroscopy during endovascular aneurysm treatment.

Materials and Methods

A retrospective chart review was conducted for 131 consecutive cerebral aneurysm embolizations by three neurointerventionalists at a single institution. Allowing for a transition period, the periods from January 2012 to August 2012 (Time Period 1) and February 2013 to July 2013 (Time Period 2) were analyzed for radiation exposure, contrast administration, fluoroscopy time, procedure time, angiographic results, and perioperative complications. Two neurointerventionalists (Group 1) used a conventional 2D roadmap for both Time Periods, and one neurointerventionalist (Group 2) transitioned from a 2D roadmap during Time Period 1 to a 3D overlay roadmap during Time Period 2.

Results

During Time Period 2, Group 2 demonstrated reduced fluoroscopy time (p<0.001), procedure time (P=0.023), total radiation dose (p=0.001), and fluoroscopy dose (P=0.017) relative to Group 1. During Time Period 2, there was no difference of immediate angiographic results and procedure complications between the two groups. Through the transition from Time Period 1 to Time Period 2, Group 2 demonstrated decreased fluoroscopy time (p< 0.001), procedure time (p=0.022), and procedure complication rate (p=0.041) in Time Period 2 relative to Time Period 1.

Conclusion

The monoplane 3D overlay roadmap technique reduced fluoroscopy dose and fluoroscopy time during neurointervention of cerebral aneurysms with similar angiographic occlusions and complications rate relative to biplane 2D roadmap, which implies possible compensation of limitations of monoplane fluoroscopy by 3D overlay technique.

Estimating effective dose from 3D imaging with interventional fluoroscopy systems using limited exposure data

BACKGROUND

Estimations of the effective dose from three-dimensional (3D) rotational imaging with interventional fluoroscopy systems are hampered by the fact that not all systems provide individual exposure values for each projection image included in the examination.

PURPOSE

To investigate the error in resulting effective dose introduced by not using individual exposure values for each projection image in the dose calculations for 3D rotational imaging with interventional fluoroscopy systems.

MATERIAL AND METHODS

An interventional fluoroscopy system was used to acquire images of two anthropomorphic phantoms. Calculations of the effective dose were performed using two different methods: 1, using individual exposure values for each projection image; and 2, using the mean tube voltage and the total dose-area product (DAP), evenly distributed over a selection of projection images. The second method was also tested in hypothetical examinations to investigate the effects of worst-case scenarios regarding the effect of exposure asymmetry on the error.

RESULTS

The error in resulting effective dose obtained when simplifying the dose calculations by using Method 2 instead of Method 1 was within ±14%. The error increased slightly for the worst-case scenarios but was still smaller than ±20%, regardless of anatomical region, tube voltage variation, and patient size.

CONCLUSION

Given the uncertainties associated with the effective dose concept as well as of reported DAP values, the present study indicates that dose calculations based on average exposure values distributed over a smaller selection of projection angles can provide reasonably accurate estimations of the radiation doses from 3D imaging using interventional fluoroscopy systems.